The present disclosure relates generally to organic light emitting diodes (OLEDs) and display devices that include OLEDs. Contemplated display devices include, but are not limited to, light sources, image displays, visual indicators, and other devices that utilize one or more light sources to fulfill their function.
Although OLED devices can efficiently generate light, much of the light that is produced is not transmitted but remains trapped within the device. In many conventional devices, 25% or less of the light produced emanates from the device while 75% or more of the light is trapped within the device (45% or more trapped within the device's organic layers, and 30% or more trapped within inorganic layers, i.e., glass substrate). A schematic illustration of a bottom-emission OLED device, where light emission occurs through the substrate, is shown in FIG. 1A. A schematic illustration of a top-emission OLED device is shown in FIG. 1B. Each device includes a top electrode 2, one or more active layers 4, and a bottom electrode 6 formed over a supporting substrate 10. In a bottom-emission device, the bottom electrode may be transparent, while in a top-emission device, the top electrode may be transparent. The arrows in each figure depict the direction of light emission.
In view of the foregoing, one aspect of the present disclosure relates to improving the light transmission of organic light emitting diodes. A further aspect of the present disclosure relates to protecting organic light emitting diodes from adverse reactions with air and/or moisture, thus extending their lifetime. The technology of the present disclosure can be used to enhance the performance of organic light emitting diodes.